A MIG welding torch allows a user or robot to direct an electrode metal wire and welding current toward a target workpiece. The electrode metal wire is continuously fed from a spool and consumed as the welding process progresses. Components of a MIG welding torch include consumables such as a contact tip, a nozzle, and a diffuser. The electrode metal wire feeds through a passageway in the contact tip. The welding current flows through the diffuser and the contact tip. The inert gas flows from passages in the diffuser, and the nozzle guides the gas towards the tip of the electrode metal wire.
The contact tip and diffuser are typically attached by threads. Mechanical vibration as well as temperature cycling may cause this threaded connection to loosen.